You are Here: Home >< Maths

# Working out different to mark scheme

Announcements Posted on
TSR's new app is coming! Sign up here to try it first >> 17-10-2016
1. Hello,

When doing binomial in MS1B/SS1B, I have never been taught to write out my working this way:

Instead we were taught to write out what we'd input into out calculator: binomialpdf (or binomialcdf) i.e. (Binomialpdf(50, 0.15, 6)).

I'd still get the right answer but I was wondering whether I'd be penalised by doing it this way.

Thanks.

Posted from TSR Mobile
2. (Original post by nemanuel96)
Hello,

When doing binomial in MS1B/SS1B, I have never been taught to write out my working this way:

Instead we were taught to write out what we'd input into out calculator: binomialpdf (or binomialcdf) i.e. (Binomialpdf(50, 0.15, 6)).

I'd still get the right answer but I was wondering whether I'd be penalised by doing it this way.

Thanks.

Posted from TSR Mobile
Do you understand how they do it in the mark scheme? I'd do that method in your working out, and use your calculator to check.

Your calculator is doing all of the work for you really, and it's not showing you understand the formula for the binomial distribution, so I'm not sure if you would get marks for writing what you put into your calculator.
3. (Original post by rayquaza17)
Do you understand how they do it in the mark scheme? I'd do that method in your working out, and use your calculator to check.

Your calculator is doing all of the work for you really, and it's not showing you understand the formula for the binomial distribution, so I'm not sure if you would get marks for writing what you put into your calculator.
This is the "what if I just write the answer" question all over again and you generally miss a method mark or indeed all of the marks.

Binomial coefficients flow from understanding permutations and combinations and just using the calculator divorces understanding from answering questions.

You need to be able to look at the binomial coefficient formula and really understand where each part comes from in terms of Ps and Cs.
4. (Original post by rayquaza17)
Do you understand how they do it in the mark scheme? I'd do that method in your working out, and use your calculator to check.

Your calculator is doing all of the work for you really, and it's not showing you understand the formula for the binomial distribution, so I'm not sure if you would get marks for writing what you put into your calculator.
Not at all. I'll do my best to learn it. Any help would be appreciated though.

I thought so too but our teacher seemed to not penalise us during homework/assessments/mocks.

Posted from TSR Mobile
5. (Original post by nerak99)
This is the "what if I just write the answer" question all over again and you generally miss a method mark or indeed all of the marks.

Binomial coefficients flow from understanding permutations and combinations and just using the calculator divorces understanding from answering questions.

You need to be able to look at the binomial coefficient formula and really understand where each part comes from in terms of Ps and Cs.
Like I said, we've never actually been taught to do it this way. I have however tried to learn it - I've kind of developed the 'template' per say as to "what number goes where" when writing the expression:

Hopefully this should help, as when looking at the mark scheme it only requires you to write out the expression for the probability density function not the cumulative.

Posted from TSR Mobile

## Register

Thanks for posting! You just need to create an account in order to submit the post
1. this can't be left blank
2. this can't be left blank
3. this can't be left blank

6 characters or longer with both numbers and letters is safer

4. this can't be left empty
1. Oops, you need to agree to our Ts&Cs to register

Updated: May 23, 2016
TSR Support Team

We have a brilliant team of more than 60 Support Team members looking after discussions on The Student Room, helping to make it a fun, safe and useful place to hang out.

This forum is supported by:
Today on TSR

### How does exam reform affect you?

From GCSE to A level, it's all changing

Poll
Useful resources

### Maths Forum posting guidelines

Not sure where to post? Read here first

### How to use LaTex

Writing equations the easy way

### Study habits of A* students

Top tips from students who have already aced their exams